German Patent Publication DE 3,203,346 A1 (Klopp et al.) discloses a carrier body for supporting a roof railing on a vehicle roof. Each railing rod is supported at each of its ends by a separate carrier body comprising at least two sections having a longitudinal interface for interconnecting the sections. The railing rod itself is a hollow tubular section, the ends of which are not deformed. Rather, each rod end is received in a horizontally facing socket of the respective separate carrier body. The carrier bodies at each end keep the railing rod spaced upwardly from the roof surface. Each carrier body or mounting foot comprises a flat smooth outer surface and hollow spaces reinforced by inner ribs formed by sections made of synthetic material. The sections are assembled in the form of a shell and a cover to form a closed component, whereby the sections have projections and recesses that are complementary to each other so that the two sections can be attached to each other by interlocking snap locks. Additionally, the carrier or mounting feet may be enclosed by a casing. A securing device is provided on the side of the mounting foot facing the roof surface, for example, in the form of a threaded bore or a threaded insert into which a mounting screw is screwed, whereby the mounting screw extends through the vehicle roof or through a roof reinforcing member.
The just described conventional mounting feet for roof racks must be of stable, solid construction because the entire weight is taken up by the mounting feet. Thus, the mounting feet are either entirely solid or are reinforced by ribs to be able to take up the stress caused by the loads carried by the roof rack. Such constructions involve a substantial effort and expense for producing the mounting feet.
German Patent Publication DE-OS 4,223,898 A1 (Lumpe et al.) discloses a roof rack railing, the ends of which are bent over and widened out to form a mounting foot by fitting a mounting insert into the widened railing end. Such a construction poses a problem because the railing end itself can be secured to the roof surface only through the insert. To solve the problem Lumpe et al. disclose an insert that is shaped to fit into the widened bend end of the railing. The insert in turn is provided with a threaded bore for securing the insert to the vehicle roof. However, the connection between the insert and the railing appears to rely solely on a location fit between the inner surface of the widened railing end and the respective insert. Such a connection may not be satisfactory where the roof rack is intended for carrying substantial loads.